Wheel dresser



March 12, 1968 J. GRABOWSKI 3,372,687

WHEEL DRES SER Filed April 19, 1966 2 Sheets-Sheet 1 INVENTOR.

JERZY GRABOWSK! BY 01 73/12 Luv:

AGENT March 12, 1968 J. GRABOWSKI 3,372,687

WHEEL DRES SER Filed April 19, 1966 2 Sheets-$heet 2 Fig.3

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INVENTOR. JERZY GRABOWSKI 6 FEW AGENT United States Patent Office 3,372,637 Patented Mar. 12, 1968 3,372,687 WHEEL DRESSER Jerzy Grabnwslri, 17 St. Charles Ave, West Caldwell, NJ. 070% Filed Apr. 19, 1966, Ser. No. 543,581 Claims. (Cl. 125--1l) This invention relates to wheel dressers, and in particular, to those dressers used to shape and form the face of a rotary grinding stone.

In particular, this invention relates to Wheel dressers having internal means for ratio translating and particularly with cam actuated motions, a multiple of linear motions, to two-dimensional tracing whereby a diamond stylus dresser is advanced to and into the face of a stone and by means of an internal cam means, shapes and forms the contour of the grinding face of a cylindrical grinding wheel.

More particularly, this invention relates to a wheel dresser adapted to be removably mounted upon both cylindrical and surface-type grinders and which, by means of internal cams and mechanism, the dresser is able to simultaneously translate into both X and Y motions the path of a diamond stylus dresser so as to shape and form the face of a cylindrical grinding wheel.

The widespread use of shaped grinding wheels to grind and form the surface of cylindrical and flat pieces is highly commercial and also is well-known in the art and is no subject of this invention. However, the precise and economical shaping of these wheels has been and is a problem and when a single point dresser is used the ac curate formation of the faces of these grinding wheels require care and expert use of a diamond stylus dresser precisely traversing the face of these wheels that are used to form and produce the final product. Most of the known tools of the present day which are used to shape and form the faces of these grinding wheels are the type known as a pantograph mechanism, or of a type having slide cams. Most of this apparatus is large, bulky and expensive, and is hard to set up and establish a predetermined position for the precise shaping of certain grinding wheels.

It is, therefore, an object of this invention to provide apparatus adapted to receive and use easily formed internal cams for activating the mechanism in a ratio manner so that the movement is translated into the X and Y motion and a diamond stylus dresser is readily positioned and adapted to cut and shape the 'face of a grinding wheel. The apparatus to be herein and after described is light in weight, easy to maintain, easy to mount and use, and economical of construction.

As the mounting of a tool dresser onto the existing grinder for the shaping of the wheel is a large part of the cost and expense of the machine operation, it is essential that apparatus of this type be readily mounted, easily adjusted, and nearly foolproof in operation. The high accuracy required of the wheel dresser in the shaping of the face of the grinding wheels of today is only an exemplification of the modern techniques used in forming a grinding stone so that the complete contour of the piece being ground, which is often too hard to be shaped by any other means, is such that the face of the stone is often brought to close tolerances of a very few thousandths, if not less than a thousandth of an inch. Since the cost of producing the forms necessary to translate the motion of the diamond dresser into an X and Y motion or into two-dimensional motion, so as to shape the face of the stone is not the least of the cost of operation and maintenance of these Wheel dressers, it is essential that dressers of this type, as exemplified by this invention, require the minimum amount of cost in producing the control cams necessary to actuate the mechanism to provide the X and Y motion of the dresser. High reliability is also an extremely necessary essential of this type of apparatus, and it is the object of this invention to provide a tool which is repeatedly and rapidly accurate, and with the accuracy dependent upon the simple machining of the cams providing for the precision of the translated motion.

The invention accordingly comprises a preferred apparatus embodying the features of construction, combination of elements, and arrangement of parts and relation or order of one or more of these parts with respect to each of the others all as exemplified in the following detailed disclosure, the scope of the application of which is indicated in the appended claims.

Further objects and advantages of the invention will become apparent as the description of a preferred embodiment proceeds in connection with the accompanying drawings wherein:

FIG. 1 is an isometric view of the dresser of this invention with the cover removed and showing the internal construction of the apparatus of this invention;

FIG. 2 is a plan view of the apparatus of this invention in a reduced scale, and showing the arrangement of the parts in relationship to the X and Y motion required to dress and shape a grinding wheel;

FIG. 3 is a sectional view generally taken on the line 33 of FIG. 2; and

FIG. 4 is a sectional view generally taken on the line 44 of FIG. 2.

Referring now to the drawings in which similar numbers refer to similar parts throughout this specification; a base 10 carries upon it a movable body 12 which is longitudinally retained in relation to the base by means of a roller guideway 14 as best seen in FIG. 4. Internally of the base 10, there is a rotatable longitudinally retained adjusting screw 15 which is retained in the base 10 and has a threaded end portion engaging a threaded block 16 which is retained in the base It). This threaded block fixedly retains an upwardly extending cam follower 18 to be more fully described. The upper portion of body 12 is closed by a cover 20 having mounted thereon a gear motor 22 which may be powered by an electrical drive means from an electrical motive source not shown. This gear motor has formed on the end of its drive shaft a drive dog 23 adapted to seat in and engage a slot 24 formed in the upward end of a cam drive shaft 25. The upper portion of shaft 25 is maintained in a fixed relationship to the body 12 by means of a hearing block 26 having mounted therein a bearing 27 supporting the upper end of the shaft 25. Intermediate the ends of this shaft (there is formed a key means 28, with the lower portion of this shaft) supported in a fixed position by means of a bearing 29 mounted in a suitable boss formed in the body 12. Sideably mounted upon the shaft 25 is an upper cam 30 and a lower cam 31 each having a key-way engaging the key 28 so that, although readily removable from shaft 25, the cams 30 and 31 are nevertheless maintained in fixed rotational relationship to the shaft during the operation or rotation of the shaft.

Referring once again to FIG. 3, it is to be noted that cam follower 18 extends upwardly from block 16 and engages the outer surface of cam 31. By means of spring 32 having one end attached to base 10 and having the other end attached at its outer left edge to the body 12 at point 33, the cam 31 is urged and maintained against cam follower 18 as it is rotated by shaft 25.

Referring now to upper cam 30, it is to be noted that cam follower 35 is fixedly mounted upon a slide block 36 which is longitudinally movable in the body 12. The block 36 carries upon it a stop block 37 which, as it is moved causes arm 38, having followers 39 mounted thereon to be moved in response to the movement of the stop block 37. The two followers 39, in the present instance, are exactly the same distance from pivot point 40 which is fixed to the body 12. The followers are also at right angles to each other. It is to be here noted that the motion derived from the rotation of cam 30 provides a perfectly linear motion to slide 42 as the motion is transferred by means of arm 38. As seen in the preferred embodiment the arm ratio is one-to-one but the ratio may be increased to ratios such as two-to-one; three-toone or more. As viewed in FIG. 2, the right-hand follower 39 engages the forward moving slide 42 which carries on its end a stylus holder 43 adapted to hold a diamond dresser point 44 by which means a stone may have its face formed to the desired X and Y shape as determined by the cams 3t and 31. It is to be noted that ball bearings 47 are mounted in a bearing way 48 formed as part of the body 12. In like manner, bearings 49 are mounted in a bearing way 50, which is also a part of the body 12.

It is to be further noted in FIGS. 2 and 4 that the exterior portion of the forward slide 42 is covered by a bellows 52 in a conventional manner and is provided so as to prevent grinding dust and debris from entering the interior portion of the apparatus or mechanism of this invention. Referring to FIG. 3, it is to be noted that a spring 54 has one end disposed so as to engage the right end wall of the body 12 and has its other end disposed to engage a spring stop 55 attached to and extending downwardly from slide 36. This spring 54 urges the slide 36 leftward so that the cam follower 35 engages the outer peripheral cam surface of cam 30 and maintains the follower in a biased relationship to this cam. In like manner, referring to FIG. 4 the spring 56 engages the right-hand edge or end wall of body 12 and has its left end engaging a spring stop 57 attached to and extending downwardly as a part of the forward slide 42. In this manner, spring 56 urges the forward slide 42 into engagement with the cam follower 39 mounted on the end of arm 38.

Use and operation.

In use, the apparatus above described, is provided with two cams 30 and 31 mounted on shaft and maintained in fixed relationship to each other and to the shaft by means of key 28. The outer contour of these cams are pre-cut from calculations adapted to give precise movement to the diamond dresser point 44. It is to be here noted that these cams 3t and 31 have approximately five times the circumferential distance as the length of the arm embodied in the arm 33. It is also noted that arm 38 gives a one-to-one motion to dresser point 44 in response to the rotation of cams and 31. The lower cam 31 engaging cam follower 18 is laid out so that the X motion, as indicated by the arrows and X in FIG. 2, is translated into the throw of cam 31, and as the cam follower 18 lies upon the center line of the movement of the lower guideway 14, the cam is readily calculated to give a precise longitudinal or X coordinant movement to the body 12. In this manner, the body 12 transcribes back and forth the desired path and dwell of the X movement as determined by the calculator of the cam to take and provide the desired face in the stone 45. In like manner, the upper cam 30 has its axis on the center line of the slide 36, and as it is rotated engages the cam follower so as to move cam follower 39 forwardly and backwardly in the direction of the arrows shown in FIG. 2, and in this manner, as the block 37 engages the cam follower 39 adjacent thereto, causes arm 38 to pivot on pivot point 40, and as the arm 38 is pivoted, the right end cam follower 39, as seen in FIG. 2, engages the rear surface of the forward slide 42, causing it to move in the Y-Y motion as indicated by the arrows. Cam 30 may be readily made of about five times the length of a direct slide cam that would actuate the diamond 44 if the direct cam slide was in a one-to-one ratio. As the circumferential length of cams 3t) and 31 are much greater than the length of a one-to-one slide or direct cam, the accuracy required for making a cam 30 or 31 is much less than a direct ratio cam. Also if cam 30 or 31 is made as accurate as a direct or slide cam the resultant controlled movement of diamond 44- is that much greater than the direct cam.

When mounting this apparatus upon the table of a grinder or u on a base of a grinder so that the point 44 may transcribe the desired face contour in stone .5, the base 10 is clamped to the body or the table, and by means of screw 5, the relative position of block 16 is changed so as to urge body 12, either to the right or to the left, as shown by the arrows above cover 20 in FIG. 3, and in this manner the point 44 is brought into the desired starting relationship with the stone 45. As the motor or propulsive means 22 is started, the shaft 25 is rotated, the cams 30 and 31 engage the corresponding cam followers, causing simultaneously X motion and Y motion in response to the calculated contour formed on the cams 30 and 31.

Although the apparatus shown in the FIGS. 1, 2, 3 and 4 is of reduced scale, it is to be noted that as reduced practice this apparatus may be in the nature of approximately nine inches long by five or six inches wide and may be five or six inches high, not including the gear motor 22 extending above the cover 20. A compact apparatus of this size which preferably has the housing and several of the internal components made of aluminum or other light weight material, provides a unit very light and easy to mount, and having very low mass so that it is readily adapted to any grinding apparatus commonly used. It is to be noted that the ball races and balls used as bearings for the several longitudinal movements having been selected as an illustrative of a design of anti-friction means, but it is to be noted that other guides or slides can be very well made and used without changing the scope or efficiency of this apparatus.

Although the apparatus has been shown as illustrative of cams having a five-to-one rotational ratio with a linear movement, this ratio is not necessarily a fixed ratio so that earns can and the embodiment may be altered to give cam ratios to linear movement ratios of other than fiveto-one such as, for example, three-to-one, four-to-one, two-to-one, or if it is desired, a one-to-one ratio. It is to be further noted that in utilizing strictly linear motion, and a strictly one-to-one ratio of the two arm portions of arm 38, the cams are extremely simple to calculate and to construct in that the throws or desired distance of the cam follower movement is always on a direct line extending from the axis of the cam.

Although the particular apparatus herein shown and described in detail is fully capable of attaining the objects and providing the advantages herein before stated, it is to be understood that it is mere-1y illustrative of the presently preferred embodiment of my invention and that I do not mean to limit myself to the details of construction or design herein shown other than as defined in the appended claims.

I claim:

l. A wheel dresser adapted to move a diamond dresser point and the like along both X and Y axes and to and into the face of a rotary grinding wheel to precisely form the face of the wheel, the dresser comprising: (a) a base; (b) a body carried by and movable on the base and in the direction of the X-axis; (c) a cam shaft carried by and rotatable in the body; (d) means to rotate the cam shaft at a determined rate and direction; (e) a pair of cams removably mounted on the cam shaft and having their contours formed to a calculated and selected shape said cams having means for positioning the cams in a selected orientation on the cam shaft; (f) a cam follower carried by a member slidably retained in the base, the follower member movable in the direction of the X axis and to a selected position in response to a means for moving the member, the follower disposed so as to engage the outer contour of one of the cams as it is rotated and in response thereto to thereby move the body in the direction of the X-axis; (g) a first slide block movable in a guideway in the body and in the direction of the X-axis, said slide block having a cam follower on one end, said cam follower being adapted to engage the outer surface of the other cam as it is rotated so as to move the slide block; (h) a stop block carried by said slide block; (i) a bell crank arm pivotally mounted on and carried by the body, one portion of the arm extending to the first slide block and said end of the arm having means adapted to engage the stop block and to be moved by the stop block as it is moved on the X-axis; (j) a second slide block movable in a guideway in the body and in the direction of the Y-axis, said second block having an engaging face formed at one end and on the other end a dresser point holding means; (k) a second portion of the pivotally mounted arm extending to the second guide block, the outward end of said second portion having means adapted to engage and move the second slide block; and (1) means for maintaining the cam followers in engagement with their respective cam contours so that as the cams are rotated the cam follower carried by the base causes the body to move along the X-axis and the cam follower on the first slide block moves the arm to cause the second slide block to move along the Y-axis and as the cams are rotated the resultant movement provides a path of the dresser point along a combined X and Y axis in response to the contour of the rotating cams- 2. A wheel dresser as in claim 1 in which the arm has portions of determined length providing a precise ratio, the portions being at right angles to each other, and in which the means to engage are rollers carried by the outer arm portions.

3. A wheel dresser as in claim 2 in which the means for maintaining the cam followers in engagement are biasing means: one of the biasing means extending from the base to the body, one of the biasing means extending from the body to the first slide block and one of the biasing means extending from the body to the second slide block.

4. A wheel dresser as in claim 3 in which the means for moving the cam follower member in the base is a lead screw rotatable in and longitudinally retained in the base and threadly engaged with the cam follower member.

5. A Wheel dresser as in claim 2 in which the cam shaft has a key means and each of the cams are provided with a key engaging means.

6. A wheel dresser as in claim 5 in which the first and second slide blocks are carried in and are movable in a roller guideway in the body.

7. A wheel dresser as in claim 6 in which the effective portions of the arm are the exact same length and are at right angles to each other and in which the X and Y axes are at right angles to each other.

8. A wheel dresser as in claim 2 in which the axis of the cam shaft and the axes of the cam followers engaging the cams all lie in a common plane at least parallel to the X-axis.

9. A wheel dresser as in claim 8 in which the means to rotate the shaft is a motor mounted on a cover removably mounted on and covering an open top portion of the body.

10. A wheel dresser as in claim 2 in which there is provided a spring means mounted between the base and body and adapted to urge the cam follower carried by the member slidable in the base against and in contact with one of the cams; and in which a spring means is provided between a portion of the body and an engaging means on the first slide block, said spring adapted to urge and maintain the cam follower mounted on the first slide block in contact with the contour of the other cam; and in which a spring means is provided between a portion of the body and engaging means on the second slide block so as to urge the second slide block into engagement with one of the rollers carried by the arm so as to move the arm and its other arm portion and roller into engagement with the stop block on the first slide block; and in which the cam shaft has orienting means adapted to engage complimentary means in the mounting means of the cams so as to provide precise rotational alignment of the cams; and in which the axis of the cam shaft and the axes of the cam followers engaging the contours of the cams all lie in a common plane at least parallel to the X-axis; and in which the circumference of the cams is greater than the length of the arm portion engaging the stop 'block of the first slide block.

References Cited UNITED STATES PATENTS 2,317,411 4/ 1943 Seyferth -11 2,326,073 8/1953 Seyferth 125-11 2,658,496 11/1953 Hoglund 125--11 3,212,491 10/1965 Balamuth 12511 HAROLD D. WHITEHEAD, Primary Examiner. 

1. A WHEEL DRESSER ADAPTED TO MOVE A DIAMOND DRESSER POINT AND THE LIKE ALONG BOTH X AND Y AXES AND TO AND INTO THE FACE OF A ROTARY GRINDING WHEEL TO PRECISELY FORM THE FACE OF THE WHEEL, THE DRESSER COMPRISING: (A) A BASE; (B) A BODY CARRIED BY AND MOVABLE ON THE BASE AND IN THE DIRECTION OF THE X-AXIS; (C) A CAM SHAFT CARRIED BY AND ROTATABLE IN THE BODY; (D) MEANS TO ROTATE THE CAM SHAFT AT A DETERMINED RATE AND DIRECTION; (E) A PAIR OF CAMS REMOVABLY MOUNTED ON THE CAM SHAFT AND HAVING THEIR CONTOURS FORMED TO A CALCULATED AND SELECTED SHAPE SAID CAMS HAVING MEANS FOR POSITIONING THE CAMS IN A SELECTED ORIENTATION ON THE CAM SHAFT; (F) A CAMS FOLLOWER CARRIED BY A MEMBER SLIDABLY RETAINED IN THE BASE, THE FOLLOWER MEMBER MOVABLE IN THE DIRECTION OF X AXIS AND TO SELECTED POSITION IN RESPONSE TO A MEANS FOR MOVING THE MEMBER, THE FOLLOWER DISPOSED SO AS TO ENGAGE THE OUTER CONTOUR OF ONE OF THE CAMS AS IT IS ROTATED AND IN RESPONSE THERETO TO THEREBY MOVE THE BODY IN THE DIRECTION OF THE X-AXIS; (G) A FIRST SLIDE BLOCK MOVABLE IN A GUIDEWAY IN THE BODY AND IN THE DIRECTION OF THE X-AXIS, SAID SLIDE BLOCK HAVING A CAM FOLLOWER ON ONE END, SAID CAM FOLLOWER BEING ADAPTED TO ENGAGE THE OUTER SURFACE OF THE OTHER CAM AS IT IS ROTATED SO AS TO MOVE THE SLIDE BLOCK; (H) A STOP BLOCK CARRIED BY SAID SLIDE BLOCK; (I) A BELL CRANK ARM PIVOTALLY MOUNTED ON AND CARRIED BY THE BODY, ONE PORTION OF THE ARM EXTENDING TO THE FIRST SLIDE BLOCK AND SAID END OF THE ARM HAVING MEANS ADAPTED TO ENGAGE THE STOP BLOCK AND TO BE MOVED BY THE STOP BLOCK AS IT IS MOVED ON THE X-AXIS; (J) A SECOND SLIDE BLOCK MOVABLE IN A GUIDEWAY IN THE BODY AND IN THE DIRECTION OF THE Y-AXIS, SAID SECOND BLOCKING HAVING AN ENGAGING FACE FORMED AT ONE END AND ON THE OTHER END A DRESSER POINT HOLDING MEANS; (K) A SECOND PORTION OF THE PIVOTALLY MOUNTED ARM EXTENDING TO THE SECOND GUIDE BLOCK, THE OUTWARD END OF SAID SECOND PORTION HAVING MEANS ADAPTED TO ENGAGE AND MOVE THE SECOND SLIDE BLOCK; AND (1) MEANS FOR MAINTAINING THE CAM FOLLOWERS IN ENGAGEMENT WITH THEIR RESPECTIVE CAM CONTOURS SO THAT AS THE CAMS ARE ROTATED THE CAM FOLLOWER CARRIED BY THE BASE CAUSES THE BODY TO MOVE ALONG THE X-AXIS AND THE CAM FOLLOWER ON THE FIRST SLIDE BLOCK MOVES THE ARM TO CAUSE THE SECOND SLIDE BLOCK TO MOVE ALONG THE Y-AXIS AND AS THE CAMS ARE ROTATED THE RESULTANT MOVEMENT PROVIDES A PATH OF THE DRESSER POINT ALONG A COMBINED X AND Y AXIS IN RESPONSE TO THE CONTOUR OF THE ROTATING CAMS. 